In the course of testing semiconductor devices and circuits it becomes necessary to contact and electrically probe the devices and circuits to ascertain their function and determine failure mechanisms. To accomplish this, a finely pointed probe tip or group of finely pointed probe tips is brought into contact with the device or circuit by using pads connected to the device or circuit. As semiconductor devices become smaller and circuits denser, it becomes difficult to make electrical contact with the device with conventional probes, as the probe tips are either too large or too blunt to selectively contact only the intended device or circuit because they have a propensity to contact adjacent structures. Or, the tips are so thin as to bend when contact is attempted and slide off the probe terminal target circuit being tested. When multiple probes are required, it is often not possible to bring the correct number of probe tips close enough to each other because the size of the bodies will physically interfere with one another or will block the view of the target area being tested, thereby making alignment difficult or impossible.
As a result of these problems, pads on semiconductor devices which can number several hundred are often limited by the probe assemblies or probe rings used because of the size of the probe tips. This is especially true in the street or kerf regions between active dies on semiconductor wafers, wherein special test and process monitoring devices and circuits are often fabricated. The actual devices and monitoring structures are often very much smaller than the pads connected to them. A more compact probe assembly would allow smaller pads to be used allowing more devices in the same space or the same number of devices in a smaller space.
Turning to the prior art, a commonly used probe tip is described in U.S. Pat. No. 4,956,923 to Pettingell et al. The probe tip is mounted to a cantilever beam.
U.S. Pat. No. 5,116,462 to Bartha et al. describes a method of fabricating a micro-mechanical cantilever beam with an integral tip using a semiconductor which is reactive ion etch and the an-an-isotropic etch to form molds. Both of these prior art patents are hereby incorporated by reference.